Ratchet tools are well known and are a tool suitable for applying torque to a fastener such as a nut, bolt or screw, via an appropriate drive socket (hereinafter also referred to as a fastening device) having a square drive recess which receives a square peg of a ratchet bar, for the purpose of tightening or slackening the fastener. The wrench or ratchet tool is movable relative to the fastening device in one direction only opposite to that direction in which torque is applied. Motion between the ratchet bar and the fastening device in the opposite direction is achieved by a set of angular teeth, which co-operate with a pawl to create a locking motion in the one direction only for applying torque and free movement in the opposite direction. The operation of the fastening device and fastener via a ratchet bar is much more convenient in restricted space situations than the use of a fixed bar operated socket because there is seldom a requirement to remove and reattach the fastening device operating the fastener.
Variations of known ratchet bar arrangements are exhaustive. Most mechanisms have more and more locking teeth etc. to allow a smaller angle between drive, re-position and drive, resulting in mechanisms in which the angle between drive and reposition has been substantially reduced, but as a result so has the amount of torque that can be safely applied to the ratchet bar without failure. The increasing intricacies of the ratchet mechanisms have resulted in them being intolerant to dirt or corrosion.